The Synthesis Core directly supports the research function of the University of Iowa SBRP research program[unreadable] by providing a PCB exposure mixture as well as individual PCB congeners and PCB metabolites. In support[unreadable] of the Analytical Core, this core will also provide analytical standards. Specific Aim 1 is the preparation of[unreadable] analytical and quality control/assurance standards for the Analytical Core. In close collaboration with[unreadable] the Analytical Core, which is responsible for purity control of PCB congeners and testing of prepared[unreadable] standards against certified Standard Reference Materials, the Synthesis Core will acquire or synthesize[unreadable] individual PCB congeners and prepare stock solutions for use as PCB calibration mixtures. Specific Aim 2[unreadable] is the preparation of an airborne PCB exposure mixture for in vitro and in vivo studies for Research[unreadable] Projects #1, #2, #3, and # 5. This exposure mixture will approximate the PCB congener profile of the mean[unreadable] Chicago PCB signal. The mixture will be prepared in close cooperation with the Analytical and Inhalation[unreadable] Toxicology Cores by mixing of Aroclor 1242, Aroclor 1254 and individual PCB congeners. Specific Aim 3 is[unreadable] the synthesis of PCB congeners to supplement the PCB exposure mixture in Aim 2 and for use with[unreadable] the in vitro and in vivo studies of Research Projects #1, #2, #3, and # 5. These PCB congeners will also[unreadable] be available to the Analytical Core for the preparation of analytical and quality control/assurance standards.[unreadable] Specific Aim 4 is the synthesis of methoxylated and hydroxylated PCB metabolites. Hydroxylated PCB[unreadable] metabolites will be used by Projects #1, #2, #3, and #5 for in vitro and in vivo studies. Both the hydroxylated[unreadable] and methoxylated PCB derivatives will be provided to the Analytical Core and individual research projects as[unreadable] analytical standards for the identification and quantification of (unknown) metabolites. Specific Aim 5 is the[unreadable] synthesis of quinoid metabolites of PCBs and their glutathione conjugates for Research Projects #1[unreadable] and #2. Specific Aim 6 will provide PCB sulfates needed by Project #3. All compounds will be[unreadable] synthesized, if necessary in large (gram) quantities, with straightforward synthetic approaches that are well[unreadable] established at the University of Iowa. Drawing on their extensive experience with the synthesis of[unreadable] organohalogen compounds, Synthesis Core staff will be able to synthesize every compound of interest to the[unreadable] individual research projects.